This invention relates to the retention of digital information in logic devices which can be applied as or in multi-valued digital memory elements. More specifically it relates to applying logical functions and their configurations to achieve digital information retaining effects.
The multi-valued digital memory elements can be applied in digital circuit applications where the temporary storage of multi-valued digital information is required.
There are known and different ways to retain binary digital information. There are known physical effects that put a material in one of two different physical states. A capacitor holding an electrical charge may represent a binary 1 state, while the capacitor without a certain electrical charge may represent a binary 0. Different magnetic states (such as applied in magnetic disk drives) are another example. Another example is the optical reflective state of a material such as applied in optical disks (such as CD-ROMs).
Other binary devices use logical effects. By applying binary logical functions in feedback configurations, the resulting (usually electronic) circuit retains information about its previous switching state or states. Binary flip-flops and latches are well known examples. The memory effect depends mainly on the applied logical functions.
The related art in binary digital electronic circuits comprises two classes of logic devices: combinational logic in which the output state of a logic device does not depend on its own previous state and sequential logic where the result can be influenced by its previous switching state. Binary logic memory devices such as flip-flops are sequential devices.
An n-valued digit (with n an integer greater than 2) has inherently more information content than a binary digit. Consequently a memory device that can retain an n-valued digit retains more information than a binary memory device.
Multi-valued sequential digital (memory) devices can also facilitate the usefulness of other multi-valued logic circuits.
Multi-valued logic based information retaining devices are not merely an extension of binary devices. There are currently no known general rules or methods to identify the non-binary multi-valued logic functions to create multi-valued information retaining devices. The switching model according to one aspect of the present invention will enable identifying the appropriate n-valued logic functions.
Consequently, new devices and methods to realize multi-valued information retention are required and new methods to create or identify the enabling logic functions are required.